The jack in the pulpits (the entire genus I believe) are capable of switching sexes as needed. They'll start out producing male flowers. The pollen produced in male flowers requires significantly less resources than the berries produced by female flowers. The plant will remain male as long as needed (often multiple seasons) while storing energy in it's underground corm. Once enough nutrients have been sequestered the plant will produce female flowers and upon pollination will produce the bright red berries that require a significant resource investment. After berry production the plant will often revert to male until enough new energy has been sequestered.